Vacuum servo-brake for motor-driven vehicles



J 1929 o. J. BADERTscHER VACUUM SERYO BRAKE FOR MOTOR DRIVEN VEHICLES Filed, Dec. 1926 a Sheets-Sheet 1 y 15, 1929 o. J. BADERTSCHER 3,721,290

VACUUM SERVO BRAKE FOR MOTOR DRIVEN VEHICLES Filed Dec. 1926 s Sheets-Sheet 2 y 16, 1929 o. J. BADERTSCHER VACUUM SERVO BRAKE FOR MOTOR DRIVEN VEHiCLES Filed Ded 2. 1926 3 heets-$heet 3 "IAlfll/l Patented July 16, 19 29.. v

NITED STA vacuum sERvo-BIiAxE roiz mo'ron-nmvnnvnnrcnns;

Applicatio T es 11 filed December 2, 1926, Serial No. 152,090, and in Switzerland Ibecember 14 1925.

Vacuum servo-brakes on motor driven ve-' hicles are known with which the action of the s'ervo-brake-is controlled either by means of the brake pedal or by actuating levers or pedals specially provided to that end. These known arrangements 'pre advantages. In case a special controlling device, such as a hand lever or a pedal, is provided of the levers an in large numbers in a modern car and the driver is often compelled to release important devices, such as the gas controlling device or devices for actuating a. signal, in order to operate'the device for controlling the servo-brake. This may sent various dis-.

, it involves an undesirable increase d handles already present lead to'a fatal'delay of the braking action. If the actuation is efie'c-ted by means of the brake pedal, in.

order to render the servo-brake operative, a

' change between the gas pedal or accelerator peda l and the brake pedal has to be efiected nge in case of emergency may lead ons as for instance the foot which cha to dangerous arti of the operator in and may depress the gas pedal so that the car instead of being braked suddenly dashes forward. There is a further objectionthat the actuation of the servo-brake by means of the brake pedal does not permit finely graduated brake actions owing to the lack of support of the foot on the floor and the fact that the foot has to follow the swinging servo-brake meeh movements of the car whereby a jerky braking action results.

These drawback present invention w that the gas .0 celerator peda lcver,,are used as devices for 'c anism; whereby the same devices which serve to accelerate the car 5 are now overcome by the lnch is characterlsed in l and the throttle control hand servealso to brake it. This'overc'omes the action in emergen is facilitated as bydepressingzth .above mentioned drawbacksand secures the advantages of a simplified and handier operation of the car and of an automatic braking cies inasmuch as the braking action is rendered operative when the accelerator pedal is released'so that the car is automatically braked when, for instance,

. the operator loses control owing to a;su,dd en indisposition. The starting on an incline e gaspedal the brake .is first released'and gas is glven immediately afterwards so that the diflicult manipulation with the hand brake is avoided. The braking of thecar is rendered "as-easy ay slip oil thebrake pedal.

ontrolling devices, i,. e. the acontrolling the' v i 5,721,290 IATENT OFFICE.

OTTO 3'. BADEBTSCHER, OE ZURICH, SWITZLEBILAND.

and requires as littld'power as the acceleration.

Constructional examples of the subject matter of the present invention are illustrated on the] accompanying drawings, in which:

Fig. '1 shows in a diagrammatic manner one constructional example of the braking arrangement according to the present invention; L p Fig. 2 shows the regulating valve in a vertical longitudinal section;

Fig. 3is a cross section along line III- III in Fig. 2;

Fig. 4 is asecti Fig. 2;

Figs. 5, 6 and 7 show'in diagrammatic dinal sections the regulating valvein on along line 1v 1v in longitu different working positions;

Fig. 8 shows in a diagrammatic manner the positions of the throttle valve control lever or gas lever; A Fig. 9 shows in a plan view the frame of a motor car provided with a,modified -ar-- rangement of the servo-brake, 1

Fig. 10 shows in elevation with parts shown'in section the installation of the servoto the constructional ally illustrated in Fig;

pedal or accelerator 1,1 denotes the g s ing 2. The accelerpedal with the retur ;spr ator pedal is regulating valve and is connected by'means of a lost motion deviceto the throttle valve. The lost motion device is shown as comprising a sleeve 3 fixed to the end of the accelerator rod 4 and a rod 5 displaceable in the sleeve operatlvely connected to the th parts shown 3, the free end of therod .5 'I

carrying a pin 6 guided in a slotted part 7 of the lever, 8 by'means of which the operating shaft 9 of the throttle valve is actuated. A spring 10 acts upon the lever 8 and tends to press the latter against a stop .11. At the end of the sleeve 3 anarm 12 is provided to which a rod 13 profide'dwith a collar is linked, the latter cooperating with the lever 117 of the regulating valve indicated at 101 which will be described herev inafter. The regulating valve is connected to a pipe 18 for atmospheric pressure and is connected by pipe 19 to a source of suc-' tion by a pipe 21 to the cylinder 22 of the servo-motor, the piston .23 of which is con- The explanation ofthe manner of opera nected by means of a rod 24 to the-brake tion ofthe regulating valve ma .be given pedal 25. 26 indicates the ordinary conwith reference to Figs. 5-7 and In Fig.

nection between the brake pedal and the brake gear so that .the forceacting on theservo-motor piston is transmitted to the brake gear by the brake pedal. Inpraotice this connection to the brake pedal itself may not al ays be feasible, but for purposes of explanaion of the invention this connection is sufficient.

Figs. 2-8 show the regulating valve. 101 denotes the valve casing made of cast-iron and provided with a longitudinal bore 102. At right angles to the longitudinal axis the pipe 18 leading to atmosphere and the suc' v tion pipe 19 communicate with the bore 102 to form ports admitting atmospheric pressure and suction; the pipes are connected to the casing 101 by. means of stufling boxes 105. Between the pipes 18 and 19 and on the opposite side of the bore 102 is. arranged the pipe21 which leads to the cylinder 22 (Fig. 1) of the servo-brake and-is also connected to the casing 101 by means of a stufling box 105. A difl'erential piston 107/108 is slid able in the bore 102, the two pistons 107 and 108 being connected to each other by means 7 of a rod 109; the piston 108 controlling the suction inlet having a largerdiameter than the piston 107 controlling the inlet of atmospheric. pressure and bearing against a shoulder 102 when the piston is in its position of rest. Each 'piston formsacup for a helical spring 110 and 112 respectively which at their other ends rest in cups 111 and 113- respectively the spring 110 being considerably stronger .than the spring 112. The latter serves only for returning the dif ferential iston into its position of rest as 8 G denotes the throttle control hand lever or hand gas lever, and Z the ignition lever. The extent ofangtilar movement of the hand gas'lever G is subdivided into a range 9 in which the regulations ofthe gas from a maximum gas supply to the cut-off occurs, into a range a, in which the elements of the 'regulating valve are in the position for releasing the braking action andinto a range B, which is again subdivided into a larger part b for normal braking and a smaller part S N for special braking action. As

is seen in Fig. 1 the actuating lever 117 of the regulating valve is connected to the hand gas lever as well as to the accelerator. During travel the hand gas lever is' adjusted in the range 9 so that the parts -of the regulating valve-occupy the position indicated in Fig. 2, in which the servo-brake is inoperative. If it is intended to brake the vehicle the supply of gas is first of all cut oil byturning the hand gas lever into the range n. When the lever is further turned over the range a the arm 116 presses on the cup 111 and displaces thereby the difi'erential piston into the position indicated in Fig. 5 in which the admission of atmospheric air is cut off although no braking action yet takes lace. If now the gas lever is turned into the part b of the range B, the

arm 116 further displaces the differential piston 117/118, thereby compressing the spring 112 into the position shown in Fig. 6 and opens thereby the suction inlet whereby vacuum is admitted to one side of the brake cylinder 22 and the brake operated.

In the brake cylinder 22 a certain suction well as or overcoming the frictional reis then present which also acts upon the sistances which otherwise might influence inner faces of the dilferential piston and rethe accuracy of regulating the braking ac- Xturnsthe latter through overcommg the option. The spring 1.10 has an initial tension which approximately corresponds to the resistance which the spring 112 generates at the beginning of the compression. Rings 114 are inserted in the bore 102 for limiting the movement of the cups 111 and 113. At one end of the casing 101 and transverse to'the bore 102 and below the latter a shaft 115 is mounted on which is fixed an arm 116 provided with an extension us which, by a turning motion of the shaft 115 enters the ,bore 102 and displaces the spring cup 111 and thereby the differential piston. At the end of the axle 115 projectlng beyond the" casing is fixed an arm 117 with which the rod 13 cooperates.

Fig. 2 showsthe parts of the valve in their position of rest. Fig. 5 shows the valve parts positioned for suspending of the I braking action, Fig. 6 the position for normal braking action and Fig. 7 the position for a quick or emergency braking e'fi'ect.

posing force ofthe spring 110 and compress,

*ing the latter towards the right, whereby left so that the suction inlet is again uncovered whereupon the above described action is repeated. In this manner the pressure in the brake cylinder is kept constant during every adjustment of the gas lever.

or rainy weather, the gas lever is turned up to S or N whereby a larger uncovering of the suction inlet is obtained and a correspondingly increased braking effect results; forobtaining a quick or emergency braking action the gas lever is turned directly to the position N whereby the parts of the valve occupy the positions shown in Fig. 7 and a 12c According to the condition of the road, i. e. if the vehicle has to be braked in snowy,

' the gas lever is returned into 'the' neutral The operation of the ,above 1 position' for suspending the braking action the spring 112 causes the differential piston to return into the position indicated in Fig. 2. V

In practice immediately after starting the vehicle the gas'lever is adjusted into the desired braking range and the control of the ,gas supply and of the braking is effected by means of the accelerator whereby the adjustment of-the gas lever limits the ob; tainable maximum braking efiect. By suitably depressing the accelerator a locking of the wheels may be prevented.

described servo-brake arrangement is as follows:;

The position of the parts illustrated in full lines in Fig. 1 corresponds to the position of the accelerator pedal 1 designated by N, ife. the neutral position. Thereby the throttle valve is closed so that no gas is supplied to the motor, and the parts of the regulating valve occupy the position illustrated in Fig. 2 in which no braking action occurs. During thev running of the car the accelerator pedal is depressed from the neutral position N to the position'G indicated in dash and dot lines. In the position G the maximum quantity of gas is supplied to the motor, the throttle valve lever 8 occupies the position indicated in dash and dot lines in'which the throttle valve is com- 7 pletely opened as the'sleeve 3 is pushed into not differ in any way its position shown in dash and dot' lines, whilst the rod 13 is in its extreme leftposition (also shown in dash and dot lines in Fig. 1) andthe regulating valve is in the same position as explained above in. which no braking action occurs. When the accelerator is depressed between the positions N andG the supply-of gas to the motor is positioned according to the desired speed or to the gradient and the manner of utilizing the accelerator in the range NGr does from that in an ordinary car. 1

When the. foot of the operator permits the accelerator to move by the influence of the spring 2, beyond the position N into the range between N and B the rod 4, sleeve 3, rod 13 and its collar 125 is pulled towards the right, and the parts of the regulating valve*occupy the positions indicated in Figs. 6 or 7.. The lever 8 of the throttle valve remains in the position in which it abuts againstthe pin 11 and in which the throttle valve is closed and the rod 5 moves in the sleeve-3. Suction is admitted to the brake cylinder 22 and the braking action starts. -Whenithe accelerator has reached the position B (braking position) the piston of the regulating valve admitting suction is completely open and the sleeve 3, rod'13, collar 125 and lever'116 occupy the positions shown in dottedlines; in this position the maximumbraki'ng effectvis obtained.

The whole braking action is thus released as a logical consequence of the cutting ofi of the gas supply and so to speak by a passive action of the operator whereby the spring 2- yields the motive power. This action is of great importance with autobusses carrying a large number of passengers as in this case, when the driver suddenly loses the control of his vehicle owing to some physiological trouble, as soon as the foot of the driver releases the accelerator pedal the arrangement acts as a safety brake in a similar manner as the dead man cra ,..in vehicles running on rails.

In order to suspend the" braking action the accelerator pedal is depressed and when I the position N is reached the piston of the regulating valve permits air to enter the conduit 21 and the brake cylinder, the piston 23 is returned into its initial position and the brake is releasedby the ordinary means provided in the brake mechanism of the car. In the position N the rod 5 abuts against the end of the bore of the tubular with-each other, so that both serve to actuate and regulate to servo brake mechanism. The range over which the hand gas lever 55 may be turned above the segment 56 at the steering wheel 57 is subdivided into two parts, the ends of which correspond to the posi-- tions B, N and G, i. e. in the range NG" the gas supply is controlled by the hand lever andin the range NB the braking action is" so controlled. This subdivision slightly differs from that described above'with reference to Fig. 8. At the lower, end of vthe shaft 58 of the hand lever 55, which shaft is mounted in a known manner inside the steering column 59 a lever arm 60 -,1s fixed and a rod 61 sliding in a tubular melnber 62 is linked to the onearm 63 of a bell crank lever, the other arm 64 of which is provided wlth a slotted portion 65, whichcooperates with a.

pin 66 fixedin the rod'4 of the accelerator pedal 1. The throttle control hand lever 55 'is shown in its neutral position in Fig.

1; when it is turned into the extreme posi- V tion G'therod 61 resting on the bottom of the. tubular member 62 depresses the latter into the position shown in dash and dot lines and the accelerator rod 4 will be dlsplaced towards the left by the cooperation of the bell crank lever 63, 64,65 and the pin 66 and the throttle valve will be opened to supply gas to the inotor. When the hand lever 55 isturned into the position B the rod 61 ing action he has to adjust the hand lever is lifted and the.pressure of the spring 2 is now permitted to shift the accelerator rod 1 towards the right, as the rod 61 acts no longer asa stop to the movement of-the,

tubular member 62, and thereby the braking action occurs. It is thus possible to utilize the hand lever for regulating the gas supply and the braking action. When the driver wishes to utilize the accelerator pedal for regulating the gas supply and the brakto the position B whereupon the use of the accelerator pedal over the whole range G-NB is unrestricted. When the hand lever 55 is adjusted into the neutral position N a braking action will not occur when the accelerator is released as the members 61, 62 act as a stop.

Fig. 9 shows a constructional example of a vehicle for the four wheel brakes a separate servo-brake cylinder in which, instead of a single servo-brake cylinder 22 is provided for eachbrake. Each cylinder 22 is connected by means of a suction conduit 21 to the regulating valve 101 and a conduit 19 connects the valve 101 with the suction manifold 71 of the motor 70. The construction and operation of the means for actuating the valve 101 may be similarto any of the arrangements described above.

Figs. 10 and 11 show the installation ofthe servo-brake mechanism onamotor car of the Buick type. 1 1

The accelerator 1 is mounted on a lever 120 turnable about'a pivot pin 121. To the free end of the lever 120 is linked the rod 4- burettor 124 and connected by the pipe 18 to the air inlet 127 of the carburettor, and

.by the pipe 19 to the suction manifold 128 of the motor and by the pipe 21 to the cyl- -'inder 22- of the servo-b rake.- A' spring 2 is connected to the rod 4" and tends to returnthe accelerator 1 intoits highest brakingposition. Y

The brake cylinder 22is provided with an upper hollow. extension 128 in which a shaft 129 is rotatably mounted and a lever 129' is fixed to said shaft 129. The free end of the lever 129 is connected by means ofa chain 130' to the piston 23 on which a compression spring 131 act s. A short lever'132' is fixed to the shaft 129 outside of the extension 128 and the lever 132' is connected by the" the suction ofthe explosion motor, a valve brakegeariofwhichlthe equalizing beam 132' to control the admission ofsuction to'said 9 rod 26 to the brake pedal 25" and to the is indicated. The connection between the lever 129 and the piston 23 by means of a 1 chain 130 permits the depression of the brake pedal irrespective of the position of the piston'23. i

The interconnection between the hand gas lever 55 and the means for actuating the regulating valve by the accelerator 1 con sists of a toothed segment 13.3 cooperating V with the bevel wheel 134: at the end of the shaft 58 operated by the lever 55. The seg ment133 isnfixed to a verticalshaft 135 to the upper end of which is attached a lever 136 which is linked to arod 61. The latter is linked with its other'end to a lever arm 137 on a pivot 138 fixed in a bracket 139' which is mounted below-the foot board 73. I

The lever 137 is' so positioned that it cooperates with the collar 126 on ther'od 4. It will thus be seen that the adjustmentof the hand gas lever 55 effects the adjustment of the lever 137 and the latter acts as a stop to the displacement movement of the rod 4;

towards the right in Fig. 11 when the accelerator 1 is released for braking so that the desired braking effect can becontrolled by the hand gas lever as has been described above.

.The servo-brake arrangements described above are suit-able for being attached to existing motor cars or other vehicles of any make.

I claim:

1. In a motor driven vehicle; in 'combination, a servo-brake mechanism operable by suction, a valve to control the admission of suction to said 'servo-brake mechanism, a throttle valve forcontrolling the supply of gdsto said motor, a hand lever for controllingthe throttle valve, an accelerator pedal,

means .to operatively connect said accelerator pedal to said controlling, valve and to connect. said accelerator pedal. to said throttle 'valve, both connecting. means including a lost n otion device, and means to intercon nect said means connected to said 'a'ccelerator pedal to said throttle control hand lever,

the latter means including a stop, whereby .with the throttle control hand lever adjusted in the braking position a release of the accelerator pedal causes an actuation of'said control valve and thereby an operation of the servo-brake mechanism whilst adepression of the accelerator pedal causes said throttle valve to be opened -for supplying gas to the motor, and with the throttle control hand lever adjusted in'its'neutral position the accelerator pedal is locked in its neu ral position as regards the braking action which is then prevented when the accelerator pedal is released.

2 In amotor driven vehicle, in combination, a servo-brake-mechanism operable'by servo-brake mechanism and comprising a casing having an inlet for suction and an inlet for atmospheric air, both inlets being controlled by a tubular ,valve body having differential pistons of' difi'erent diameters, a spring acting on one end of said differential piston, a more powerful spring acting on the other end of said differential piston and tending to press the differential piston into the inoperative position, and a lever to cooperate with said differential piston for displacing the latter, said'springs in cooperation with thesuction on the pistons of different diameters automatically causing a displacement of said piston valve in order toadmit suction when the latter has been reduced by leakage losses, a throttle valve for controlling the supply of gas to said motor, an accelerator pedal, and means to operatively connect said accelerator pedal to the lever of said controlling valve and toconnect said accelerator pedal to said throttle valve, both connecting means being adapted for unindirectional motion.

In testimony whereof, I have signed my name to this specification.

OTTO J. BADERTSOHER. 

